When Games Workshop first introduced the futuristic Warhammer 40,000 setting with Rogue Trader in 1987, they expected it to be a brief diversion from their fantasy wargaming business. However the setting became popular beyond their expectations, with players using the free-form rules of Rogue Trader to draw up stats for their own creations. Over the years since then, many more books have been released, the rules have been standardised, and various army lists have been introduced (and sometimes retired).

Warhammer 40,000 is now the biggest selling futuristic wargame globally, and has a very large fan following.